Intrinsic viscosity from the Green-Kubo formula

The Green-Kubo formalism and the conventional Kirkwood-Riseman formalism (with and without hydrodynamic preaveraging approximation) are compared in the calculation of the intrinsic viscosity of a Gaussian chain. It is discussed that the Green-Kubo-type formula for the intrinsic viscosity is correct to order ε(=4-d, d being the spatial dimension). Then it is shown that without self-avoiding interaction the two formalisms give identical results to order ε; i.e., the Kirkwood-Riseman formalism is as reliable as the Green-Kubo formalism without self-avoiding interactions. With self-avoiding interaction it is argued that the validity of the Kirkwood-Riseman formalism cannot be expected.